The authors describe a case of lung cancer in a 55-year-old man who complained of back pain. Initial isotopic bone scanning showed no abnormality, however, magnetic resonance (MRI) imaging revealed bone metastasis in thoracic vertebral bone. Even when there is no typical findings of metastasis in bone scintigraphy, MRI imaging would be useful if vertebral bone metastasis is suspected. MRI imaging is an important modality to evaluate extraosseous extension and marrow invasion of metastatic tumors.